In-vitro maturation (IVM) was performed in 350 cycles for 262 unstimulated patients diagnosed with polycystic ovary syndrome who were primed with human chorionic gonadotrophin (HCG) before oocyte retrieval. In order to improve nuclear and cytoplasmic maturation, growth hormone was added to the maturation medium. Oocytes were recovered in 94.8% of the cycles, with a mean number of nine cumulus–oocyte–complexes retrieved. Within 28 h, 62% of the oocytes reached the metaphase II (MII) stage, and 17.6% were MII after a further 20 h in culture. An ongoing pregnancy rate of 15.2% was obtained, but with a high miscarriage rate, 28% of the total with a positive HCG test assessed after embryo transfer. Cytogenetic and DNA fragmentation analysis of the embryos was not fundamentally different from what is classically observed in routine IVF. This observation implies that the results are not necessarily due to compromised oocyte quality after IVM, and that endometrial receptivity should also be considered, especially in IVM cycles where the follicular phase is dramatically shortened.